itaps-parallel getVtxCoordIndex

[Mark Miller]

On Mon, 2008-09-29 at 16:28 -0700, Lori A. Diachin wrote:
> Hi All,
> 
> I came across an issue with the getVtxCoordIndex function while I was 
> testing my finite element solver code with the GRUMMP implementation of 
> iMesh.  In talking it over with Carl, we realized that we had very 
> different interpretations of what should be returned from the function 
> and that the documentation was unclear.  So we are pinging the group for 
> feedback so that we can clarify the documentation and ensure that 
> implementations are compliant...
> 
> In particular, I am attempting to request the vertices associated with 
> triangular faces and so I set the requested_entity_type to FACE, 
> requested_entity_topology to TRIANGLE, and entity_adjacency_type to 
> VERTEX.  I expect to get back 3 indices per face so that the offset 
> array is set to 0,3,6,...  This is how it's implemented in 'simple 
> mesh'.  I do not use the entity_adjacency_type argument for much of 
> anything.

This is SIMILAR to my understanding of this function. However,
in VisIt, I call it with requested_entity_topology of ALLTOPOLOGIES
because I want all the different element types in the mesh. However, for
'type' I use REGION for BOTH requested_entity_type and
entity_adjacency_type. If I recall, failing to do that caused me
problems. Since the function is ALWAYS returning the indices of
coordinates (which I think are implicitly ALWAYS associated with Vertex
entities hence 'Vtx' in the name of the function), I don't think it
makes sense to pass VERTEX as the adjacency type. I believe the function
is ALWAYS returning connectivity in termes of verticies. But, to be
honest, I am still a little confused about this method, too. 

Sorry I can't be more helpful.

Mark

-- 
Mark C. Miller, Lawrence Livermore National Laboratory
email: mailto:miller86 at llnl.gov
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